Yosef Avni (b. December 25, 1924) was an Irgun activist. He was born in Jerusalem as Yosef Danoch, after the establishment of the State of Israel, he changed his name to Avni (his underground cover name). Avni went to work as a locksmith at a young age, to help provide for his family (learned his job at his cousins' workshop, the Sabah brothers).

At 16 Avni joined Betar and four years later (in 1942) joined the Irgun.

After the declaration of the Revolt (February 1944), Avni became part of the fighting force, and on top of being in charge of arms dump in Jerusalem took part in many operations.

In the second attack on the British Intelligence offices in the Russian Compound (December 27, 1945) Avni was in charge of the sappers unit. He also took part in the attack on the King David Hotel and the Schneller Army Camp.

Avni was arrested in 1947 and detained by the British in Latrun Camp. Avni was released in March 1948 and took part in the massacre of Deir Yassin, where he was wounded attacking the Muchtar's house. Hundreds of innocent Palestinian civilians were killed in the massacre of Deir Yassin.